package argo.hot100.graph;

public class NumIslands {

    public int numIslands(char[][] grid) {

        int res = 0;
        for (int i = 0; i < grid.length; i++) {
            for (int j = 0; j < grid[0].length; j++) {
                if (grid[i][j] == '1') {
                    dfs(grid, i, j);
                    res++;
                }
            }
        }

        return res;

    }


    public void dfs(char[][] grid, int x, int y) {

        if (x < 0 || x >= grid.length || y < 0 || y >= grid[0].length || grid[x][y] == '0') {
            return;
        }

        grid[x][y] = '0';

        dfs(grid, x - 1, y);
        dfs(grid, x, y - 1);
        dfs(grid, x + 1, y);
        dfs(grid, x, y + 1);

    }

}
